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Adaptive instant record signals applied to detection with time reversal operator decomposition
Thomas Folegot1, Julien de Rosny, Claire Prada
1Laboratoire Ondes et Acoustique, Université Denis Diderot, UMR CNRS 7587, ESPCI, 10 rue Vauquelin, 75231 Paris Cedex 05, France. folegot@nurc.nato.int
The Journal of the Acoustical Society of America
|July 16, 2005
Summary
This study introduces novel pseudo-orthogonal signals for time reversal acoustics, improving target detection efficiency in dispersive environments. These adaptive signals enhance signal-to-noise ratio and accuracy in complex media like shallow water.
Area of Science:
- Acoustics
- Signal Processing
- Wave Propagation
Background:
- Time reversal arrays are essential for detection and tomography.
- Traditional impulse response measurement is time-consuming and has a poor signal-to-noise ratio.
- Existing pseudonoise signals may lack sufficient orthogonality for complex media.
Purpose of the Study:
- To develop a new family of pseudo-orthogonal signals for time reversal applications.
- To adapt these signals for highly dispersive media and guided wave propagation.
- To experimentally validate their effectiveness in target detection.
Main Methods:
- Proposed a new family of adaptive pseudo-orthogonal signals.
- Utilized these signals in an experimental ultrasonic waveguide.
- Employed the time reversal operator decomposition method for target detection.
Main Results:
- Successfully acquired 15x15 transfer functions simultaneously with high accuracy.
- Demonstrated enhanced detection capabilities in a model simulating shallow water propagation.
- Validated the effectiveness of the new signals in a reverberant and absorptive environment.
Conclusions:
- The proposed pseudo-orthogonal signals are well-suited for time reversal applications in dispersive media.
- These signals significantly improve the efficiency and accuracy of target detection.
- The experimental results confirm their utility in realistic underwater acoustic scenarios.
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